1. Field of the Invention
The invention relates to the mounting, on a flexible substrate, of miniature electronic components with solderable connection leads of the beam lead type, having straight connection leads shaped like minute beams positioned in the plane of their lower face.
2. Description of the Prior Art
Until now, it has been extremely difficult, and even impossible, to mount a beam lead component on a flexible substrate without the risk, in the shorter or longer term, of the breaking of the component or of the solderings of its connection leads because of tensile forces exerted on these leads through the flexible substrate. The first faults may appear during the mounting of the component and the subsequent faults during the operation of the equipment fitted out with such components. In the case of the faults that appear during the mounting, the breaking of the component is generally due to a depression created in the substrate during the soldering of the second connection lead or of the following ones, which causes high tensile force to be exerted on the already soldered connection lead or leads. In the other instances, the breaking is due to an exertion of tensile force on the connection leads of the component, generally prompted by the difference between, on the one hand, the heat expansion coefficients of the substrate and, on the other hand, the semiconductive material constituting the substrate. Finally, any mechanical stress exerted on the flexible support under tension is liable to prompt the same phenomenon of breakage owing to the brittleness of the beam lead components due to their very small size and the arrangement of their connection leads.
An aim of the invention is to neutralize the effects of the mechanical stresses arising from various sources, notably thermal stresses which appear on the connection leads of the beam lead components after they have been soldered to a flexible substrate.